Currently, various recording media such as disks and flash memories are used as recording media of various types of content such as movies.
There are various types of data recording formats for the recording media. For example, there is an MP4 format (hereinafter, called MP4) as a data recording format standardized in consideration of use by portable terminals such as smart phones and tablet terminals.
Many of the portable terminals have a reproduction application that can reproduce MP4 data recorded in the MP4 format. Therefore, content is required to be recorded in the MP4 format when recorded in a medium of the portable terminal.
Note that, the MP4 format is described in Patent Document 1 (JP 2014-131307 A), and the like.
Meanwhile, in recent years, content including a high dynamic range (HDR) image with extended color gamut and an extended contrast ratio to be output to a display has been widely used. The HDR image has wider expressible color gamut and a larger contrast ratio settable than a standard dynamic range (SDR) image widely used in the current 2K support displays, and can express an image close to reality seen with the naked eyes.
However, many of the displays of televisions, portable terminals, and the like currently typically used can output only the SDR image, and few displays can output the HDR image.
In the future, spread of displays that can output not only a 4K image but also the HDR image is expected.
In a case of recording the HDR image content as MP4 format data, metadata (attribute information) specific to the HDR image needs to be recorded within the MP4 file in which the MP4 format data is stored.
However, at this time, a specific definition about a metadata recording configuration of the HDR image for the MP4 file has not yet been established.